/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.read.biff;

import jxl.biff.FormattingRecords;
import jxl.biff.FormulaData;
import jxl.biff.WorkbookMethods;
import jxl.biff.formula.ExternalSheet;
import jxl.biff.formula.FormulaException;
import jxl.biff.formula.FormulaParser;

/**
 * A base class for shared formula records
 */
public abstract class BaseSharedFormulaRecord extends CellValue
        implements FormulaData {
    /**
     * The formula as an excel string
     */
    private String formulaString;

    /**
     * The position of the next record in the file.  Used when looking for
     * for subsequent records eg. a string value
     */
    private int filePos;

    /**
     * The array of parsed tokens
     */
    private byte[] tokens;

    /**
     * The external sheet
     */
    private ExternalSheet externalSheet;

    /**
     * The name table
     */
    private WorkbookMethods nameTable;

    /**
     * Constructs this number
     *
     * @param t the record
     * @param fr the formatting records
     * @param es the external sheet
     * @param nt the name table
     * @param si the sheet
     * @param pos the position of the next record in the file
     */
    public BaseSharedFormulaRecord(Record t,
                                   FormattingRecords fr,
                                   ExternalSheet es,
                                   WorkbookMethods nt,
                                   SheetImpl si,
                                   int pos) {
        super(t, fr, si);
        externalSheet = es;
        nameTable = nt;
        filePos = pos;
    }

    /**
     * Gets the formula as an excel string
     *
     * @return the formula as an excel string
     * @exception FormulaException
     */
    public String getFormula() throws FormulaException {
        if (formulaString == null) {
            FormulaParser fp = new FormulaParser
                    (tokens, this, externalSheet, nameTable,
                            getSheet().getWorkbook().getSettings());
            fp.parse();
            formulaString = fp.getFormula();
        }

        return formulaString;
    }

    /**
     * Called by the shared formula record to set the tokens for
     * this formula
     *
     * @param t the tokens
     */
    void setTokens(byte[] t) {
        tokens = t;
    }

    /**
     * Accessor for the tokens which make up this formula
     *
     * @return the tokens
     */
    protected final byte[] getTokens() {
        return tokens;
    }

    /**
     * Access for the external sheet
     *
     * @return the external sheet
     */
    protected final ExternalSheet getExternalSheet() {
        return externalSheet;
    }

    /**
     * Access for the name table
     *
     * @return the name table
     */
    protected final WorkbookMethods getNameTable() {
        return nameTable;
    }

    /**
     * In case the shared formula is not added for any reason, we need
     * to expose the raw record data , in order to try again
     *
     * @return the record data from the base class
     */
    public Record getRecord() {
        return super.getRecord();
    }

    /**
     * Accessor for the position of the next record
     *
     * @return the position of the next record
     */
    final int getFilePos() {
        return filePos;
    }
}









